[R-SIG-Mac] problem with rgl

[simone gabbriellini]

Hello List,
I have this error when I try to load rgl package:

Error in dyn.load(x, as.logical(local), as.logical(now)) :
	unable to load shared library 
"/Library/Frameworks/R.framework/Resources/library/rgl/libs/rgl.so":
   dlcompat: dyld: /Applications/R.app/Contents/MacOS/R can't open 
library: /usr/local/lib/libpng12.0.dylib  (No such file or directory, 
errno = 2)
Error in library(rgl) : .First.lib failed for 'rgl'
Error in .C(symbol.C("rgl_quit"), success = FALSE, PACKAGE = "rgl") :
	C function name not in DLL for package rgl

can you help me?

Best regards,
Simone